Land Navigation With Map And CompassPresentation Transcript
Kevin Estela Survival Instructor Wilderness Learning Center 435 Sandy Knoll Road Chateaugay, NY 12920 (518) 497-3179 www.weteachu.com Map, Compass and Land Navigation
Land Navigation Skills Importance
Many emergency situations will not become survival situations if you do not become lost.
Many people carry compasses without knowing how to use them.
The path of least resistance is usually best. A map and compass can help you travel this way.
Land Navigation is one of the first skills taught at the WLC Basic Course. We place it high in our hierarchy of skills.
Without direction, do you know where you are going in the woods?
Comfort in Location
Human beings feel comfort in knowing their place with respect to time and space. Ex. “Honey, I’m only 10 minutes from home.”
What happens to a person when they become lost? When they don’t know how long it will be until they’re home? How far they are from safety?
Short term: Fear, anxiety, rushing, mistakes, etc.
Long term: injury or death
Moss only grows on one side of a tree.
My compass will work all the time, my GPS won’t.
I won’t get lost! I’m an outdoorsman. Navigation Reality
Moss grows on all sides of trees.
You can break your compass or lose it.
Even seasoned outdoorsmen get lost, injured and die.
Why People Get Lost
Shame (Everyone is going to laugh at you “Woodsman.”)
Fear (I have to get off this mountain NOW!)
Change of Plans (Last minute tip on where the fish are biting.)
Peak baggin’ or Summit Fever (the final destination is home, not the top.)
Ego (I’m not lost, I know where I am.)
Many other factors not listed here.
Map Alone (Part I)
A map is a representation of part of the earth (sometimes entire.)
Most common used by outdoorsmen is the Topographic Map or Topo Map.
Topo maps feature imaginary lines called Contour Lines that connect areas of equal elevation.
Contour Intervals, or the elevation change between contour lines, can be low if the area is relatively flat (10 ft. per interval) or high if the area’s elevation varies greatly.
The Topo Map also shows roads, buildings, vegetation, water and many more details.
Map Alone (Part II)
With only a map, a person can perform “map recon” of the actual area without leaving the comfort of home. It allows a view of the area without actually being there.
Able to determine: nearest road, stream, place of refuge, etc.
With a map you can answer: What is the gradient like? What direction do you go towards safety? Towards danger?
A person can get an approximation of orientation (more to come on this) from looking around and laying the map as the land actually sits.
A map provides info in unfamiliar lands.
The earth is round, a map is flat. There is no way to make a round object out of something flat or vice versa (think orange peel.)
It may be years before a map is updated. Make sure to use the most recent version. There may be new developments or changes in topography not noted in older versions.
Magnetic North This is the North you will use for the majority of your navigation.
True North This is the direction of North along the Earth’s surface towards the North Pole. Direction towards the North Star.
Grid North Direction towards north pole along grid lines on a map projection. Rarely used in field orienteering and navigation for the outdoorsman.
What is Latitude? Longitude?
The earth is divided into 360 degrees of longitude (imaginary lines running North and South.) These are divided into 180 degrees East of the Prime Meridian and 180 degrees West of the Prime Meridian. These lines are widest at the center of the earth and most narrow at the two poles.
There are 180 degrees of latitude with 90 north of the equator and 90 south of the equator. These lines run parallel.
What is Latitude? Longitude?
To make location more accurate, each degree of latitude and longitude is broken down into further degrees called minutes (shown with a ‘)and seconds (shown with a “.)
A minute of latitude is approximately 1.15 miles. A second is about .02 or about 100 feet.
Therefore, a 7.5 minute map series covers approximately an area of approximately 8.625 miles by 8.625 miles. This is a total area of almost 75 square miles (74.39 to be exact.)
Your navigation skills better be accurate!
Common Map Colors and Symbols (part I)
Blue = Water (Water is usually named and is in italics)
Black = cultural features (manmade)
Brown = Earth (topographic contours)
Green = Vegetation
Purple = Revisions to Map (still present on many maps but not used anymore)
Red = Land grids and important roads
Common Map Colors and Symbols (part II)
Contour Lines and Topography
Contour lines represent elevation change. For example, the space between two lines may be 10 feet.
The closer lines are, the steeper the terrain. The farther apart, the flatter.
1:24,000 means 1 of anything on a map (1” or 1’) translates to 24,000 of the same in “real life.” Therefore, 1” on a map is 24,000” in real life. 2.5” on a map is about a mile on a 1:24,000 map. 1:25,000 is available as well as additional scales.
7.5 minute series is based on hours, minutes and seconds in latitude and longitude. Essentially, it covers 7.5 minutes of latitude and 7.5 minutes of longitude.
Prepping the Map for Use
Find the north arrows at the bottom of the map. Use magnetic north for your navigation.
Use a straight edge and draw magnetic north lines across the map parallel to each other.
Your magnetic north arrow may be folded out of view but your parallel lines will be visible.
Coat with a map sealant or Thompson’s Water Seal.
Fold carefully and place in a zip-lock bag for use.
Care For Your Map
Always carry in a zip lock bag. Treat with water proofing agent if possible (Thompson’s Water Seal works great!)
Fold it properly and avoid multiple creases if possible. Always fold it the same way.
Carry on your person, not in your pack.
Carry a spare map (they can blow away.)
Have a smaller map of the specific area photocopied for easy of use.
Map stored in Zip-lock Bag
Pacing (Part I)
A pace is not a single step. A true pace is a step with your right then left or left than right.
Derives from Roman times. 1000 (milli) paces was a Roman mile. Average pace of a Roman legion = 5.28 feet or 1/1000 th of a mile.
Pacing cannot be determined accurately by laying down a tape measure and taking a single pace. It must be done over a distance and be averaged by this formula Distance in Feet divided by Number of Paces. This determines your “Factor.”
Pacing (Part II)
Head to your local school’s outdoor track and find out how far a single lap is in feet. Usually, one lap is a ¼ mile.
Take a 50’ tape measure and mark off 100’ feet or more (528’ is nice if you can do it.)
Take normal strides and see how it changes with different footwear, weather conditions, pack weight, etc.
Learn your body and what you can do.
Personally, my factor is 5.6. Therefore, every pace I take is approximately 5.5’ long, and 94 paces equals a 1/10 th of a mile.
Learn to count “and one, and two, and three” as it makes for easy remembering.
Pace Beads and Use
4 on top represent miles and 9 on the bottom represent 1/10 th of a mile each.
For every 1/10 th of a mile, one bead is pulled down for the first 9/10 th of a mile. When a mile is completed, the 9 are returned to the top and a single mile bead from the top 4 is pulled down.
Originated with the U.S. Army Rangers to determine kilometers traveled.
Civilians in the U.S. use mile measurements more frequently and this is why they have been adapted to miles instead of kilometers.
Mile Beads 1/10 th Mile Beads
Full left stride then full right stride = One Pace
If left with only a compass, an outdoorsman can still navigate effectively and accurately over distance.
It is possible to travel in one direction and back track with accuracy to the general starting point.
A map can be drawn with scouting trips.
Even a simple button compass can give an advantage over a person without navigation tools.
Types of Compasses
Button-commonly carried in survival kits or on jacket lapels. Accuracy varies but can be generally good.
Lensatic-popularized by military. Used for calling in artillery and general orienteering. Great for intended purpose. Inability to see through base is a hindrance.
Baseplate-most common sold at most outdoor stores. Excellent for land navigation, orienteering, learning map and compass.
Electronic – Wristwatch, car, etc. Batteries fail.
Improvised – shadow sticks, magnetized needle, etc.
Button Lensatic Baseplate
Anatomy of the Compass Small Magnifying Lens Pacing Beads Lanyard made from gutted 550 parachute cord Rotating Bezel or Dial Magnetic Needle (red points North) Lid with Sighting Mirror Inclinometer Needle Directional of Travel Arrow The “Shed” Ruler/Straight edge Scales
“ Red In The Shed”
This phrase is used to remember how to take a proper bearing.
This picture shows the shed, a small outline within the bezel resembling a shed.
This is the Shed
Personal Favorite Compass
Lid acts as an extension of the baseplate for long line drawing. Also protects the compass.
Luminous bezel (activate with light.)
Small rubber knobs on base provide grip on map for neat line drawing.
Easy to manipulate with winter gloves on.
Lanyard replaced with “gutted” 550 paracord and pace beads attached.
Worn inside the shirt when actively navigating. Won’t snag on branches there.
Carried in leather case for added protection when stored in pack.
Is defined as: the angle between the geographic and the magnetic meridian at a given point, expressed in plus degrees east or minus degrees west of true north. (www.dictionary.com)
Some compasses feature declination adjustments on the bezel. We don’t advocate changing it.
What happens if you forget to change it back? Don’t get in the habit of changing it at all.
Don’t throw out that little screwdriver in case it does shift on you in the field by accident.
Use the map orientation method shown later to avoid using the declination feature on your compass.
Taking a Bearing (Azimuth) Without a Map
Make sure your bezel is turned to 0 degrees north.
Point your directional arrow on the compass towards your target destination.
Notice where the magnetic north needle is pointed.
Rotate your bezel until you place “Red in the Shed.”
When the north needle is in the shed, read your bearing/azimuth at the directional arrow. When walking this bearing, find a prominent feature along the route. Walk to it and shoot your next bearing from it. If you did have a map, you should measure the distance from your starting point to your destination and convert it to paces to ensure you don’t end up short or long.
Taking Bearings Standing Kneeling (note elbow resting on knee for stability)
Bearing with a Sighting Mirror
Hold the mirror at an angle to provide a view of the bezel.
Line up the directional arrow with a prominent point.
Make sure “red is in the shed” and read the bearing.
Note the magnetic needle in the shed Sight object here
Taking a Back Bearing (Reverse Azimuth)
To determine a back bearing or reverse azimuth, you must either add or subtract 180 degrees. If your original bearing is… Over 180 degrees then Subtract 180 degrees. Under 180 degrees then Add 180 degrees.
It is also possible to simply turn the compass around or put the opposite side of “red” in the shed. However, your bezel may rotate and you could be off. Record your bearing and do it the proper way.
Offset shooting allows a person to have an approximate idea where an object is. With a direct bearing in the situation above, a person may reach the road but not find his/her car. The curves in the road prevent a clear line of sight. With an offset, when he/she reaches the road, they will know whether to travel West or East and can avoid a long walk one way, then back the other.
Vehicle Parked Here X West East Campsite 1.) Bearing from car to campsite is originally 190 degrees Southwest 2.) Back bearing is deliberately offset fewer degrees. Vehicle will be west down the road.
Boxing an Obstacle 1.) Original Bearing 110 degrees. Walk until you can’t pass the object. 2.)Turn right, add 90 degrees and count paces until you pass the object. Now at 200 degree bearing. 3.) Turn left subtracting 90 degrees and walk past object. Back to 110 degree bearing. 4.)Turn left again, subtract 90 degrees and walk same number of paces past object as in step 2. Now bearing 20 degrees. 5.) Continue on original bearing of 110 degrees towards destination DESTINATION X STARTING POINT WATER OBSTACLE General Tip: If you turn LEFT, LOWER (the bearing.) If you turn RIGHT, RAISE (the bearing.) Boxing Left Boxing Right Subtract 90 Add 90 Add 90 Subtract 90 Add 90 Subtract 90 Subtract 90 Add 90
Importance of Accuracy Declination or Degrees Off Course Error Off Target After Walking 10 Miles 1 degree 920 Feet (280 meters) 5 degrees 4,600 Feet (1,402 meters) 10 degrees 9,170 Feet (2,795 meters)
Shadow Sticks SUN SUN Step 2.) The first shadow cast is always the Westward shadow. Mark the tip of the shadow with a twig or small stone. Step 1.) Place a stick in the ground about 3’ high. It does not have to be a perfectly straight stick. Step 3.) Mark the tip of the shadow as it creates an arc with the movement of the sun. Multiple markings are best. Noon will have the shortest shadow. Step 4.) Mark the tip of last shadow of the day. The longer you wait, the more accurate the shadow stick method is. Sun Movement Step 5.) Draw an imaginary line between the tips of the shadows. This is your East/West line. Directly 90 degrees in between is North/South. Stand on the line with your back to the stick and you are facing North. This system will give a relatively accurate indication of direction. It will remain accurate for approximately 2 weeks.
A sewing needle or straightened fish hook can be used as an improvised compass needle.
It is magnetized by rubbing it against a magnet in a single direction from the halfway point of the needle to the tip. Stroke 25 to 30 times.
If you don’t have a magnet, look for a creek. The black specks in the silt are usually magnetic. Gather it (time consuming) and use this with your needle.
The needle is floated on water and it will align North and South.
Use the Sun to help determine which end is North and South.
Take an analog watch and line up the shadow from a stick with the hour hand. Halfway between the minute hand and the shadow is North.
For a digital watch. Take a piece of paper and draw an analog watch’s face. Follow same steps.
U.S. Army Survival Manual Fig. 18-2
Compass Trouble Shooting (Part I)
Buy the best you can afford. You don’t want to “pay for it” after you buy it. Understand?
Hold your compass flat, level and away from metal or magnetic objects when reading it.
Protect your compass from damage by carrying it in a case or around your neck.
Take two compass readings with different compasses or two people with one to ensure accuracy.
Trust your instruments.
DO NOT CHANGE DECLINATION ON COMPASS BEZEL (more about this later)
Compass Trouble Shooting (Part II)
Note the 5 degree plus change in bearing due to the metal in the watch. If you wear eyeglasses, is the frame made of metal? Believe it or not, they have thrown off bearings during our courses.
Map and Compass
Provides the best combination for land navigation.
Allows a person to properly: Orient a map Plot a course Find location Much, much more!
Pair with a GPS for better accuracy. Remember, batteries fail so don’t rely on that electronic crutch.
Map with Compass (Part 1) Orienting a Map
Orienting a map means placing it on a surface and lining up magnetic north on the map with magnetic north on the compass.
To orient a map 1. Have map and compass ready. Make sure compass bezel is turned to 0 degrees north. 2. Place edge of compass on the magnetic north needle of the compass rose or one of the parallel lines you drew in preparing your map. 3. Without picking up the compass, turn the entire map with the compass on top of it until you put “Red In The Shed.” 4. Your map is now oriented to the land.
Orienting a Map Reference Picture
Compass Lined up with Magnetic North Needle.
Rotate Map and Compass without picking up compass and put “red in the shed.”
Note edge of compass aligned with MN
Taking a Bearing with Map and Compass
1. Orient Map 2. Draw a line from start to finish 3. Lay compass edge along drawn line. 4. Hold compass baseplate and turn bezel until north needle is pointing parallel to MN parallel lines. Read azimuth over the travel arrow.
First, orient the map to magnetic north.
Second, find two known points/features in the distance and find them on your map.
Third, take a bearing/azimuth to each of the locations and write it down.
Fourth, find the back bearing/azimuth for each and draw them on your map.
Finally, where the lines intersect is your approximate location.
Resection (Visual) Water Tower Fire Lookout Tower 1.) From your location, it is a bearing/azimuth of 25 degrees to the Fire Lookout Tower. Back bearing/azimuth equals 205 degrees. Note: Actual degrees shown between lines not drawn for accuracy. 2.) From your location, it is a bearing/azimuth of 55 degrees to the Water Tower. Back bearing/azimuth equals 235 degrees. 3.) Where the lines intersect here (when drawn on your map) is your location.
Triangulation (Part I)
Works on the same concept as Resection only 3 (Tri) or more bearings/azimuths are used.
The example to the right shows how to find location of self on a map.
Water Tower Radio antenna Mountain Top
Triangulation (Part II)
The example to the right shows how to find location of an object from three known places.
This is useful if communication between the known places is available.
Ex. fire crews could pinpoint where a fire is on a map. They could then determine known water sources, sources of fuel, homes in danger, etc.
Cabin Trailhead Exposed Overlook Visible Smoke
Find the big dipper. The North Star is almost directly in line with the bottom of the “lip” about 5 times the distance away of the space between the bottom two stars.
The North Star is the last star in the handle of the little dipper. The little dipper always pours into the big dipper. It is also not always visible because it is dimmer.
U.S. Army Survival Manual Figure 18-3
L.U.R.D. System U East R South D West L North 1.) Create a “rifle sight” out of a straight immovable object with two sighting points in a line. You can also use two sticks (6’ and 3’ tall) Sight with eye * 2.) Line up the sight with a star in the distance (except the North Star. 3.) Wait and record noticeable movement. 4.) Follow LURD and determine which direction you are facing. Line of sight Star MOVEMENT DIRECTION FACING LEFT NORTH UP EAST RIGHT SOUTH DOWN WEST LEFT/UP NORTHEAST RIGHT/UP SOUTHEAST RIGHT/DOWN SOUTHWEST LEFT/DOWN NORTHWEST
Some compasses are equipped with an inclinometer inside the bezel to determine angles.
This can be used to determine latitude and much more.
Turn to 90 degrees and use the straight edge on the angle you are reading.
If placed on a dash board, the inclinometer can be used to determine a vehicles traversing angle.
If carried in avalanche terrain, it can be used to aide in avalanche avoidance. (slope 35 to 45 degrees are known to be high risk)
Turned to 90 degrees Read Angle Here
Determining Latitude with a Compass (advanced skill)
Latitude is based on this simple formula, (latitude of any place in the northern hemisphere) = (latitude of the North Star at same place.)
Using the inclinometer, point the top edge of your compass at the North Star.
Read the angle with relation to the horizon and convert it to your approximate latitude.
If two people are present, one can sight, the other can read.
If one is present, the sighting mirror can be angled back to read the inclinometer without adjusting the compass.
Take multiple readings and average the results.
Always carry an emergency kit in case your compass skills fail. (include provisions for fire, shelter, signaling and water collection at a minimum)
Waterproof pad and pencil
Can you identify parts of a compass?
How do you use a map alone for general way finding?
Can you take a compass bearing? Back bearing?
What is your pace? How do you use paces to determine distance traveled.
What can throw off a compass’s accuracy?
How do you box an obstacle?
What is one way to improvise a compass?
Can you orient a map?
Can you find your location using prominent features, a map and a compass.
How do you find your way at night?
IF YOU CAN’T ANSWER THESE QUESTIONS, YOU NEED TO REREAD THIS AND PRACTICE MORE!
Wilderness Learning Center (www.weteachu.com)
United States Geological Survey (www.usgs.gov)
Suunto compasses (source of Suunto MC-2 Compass)
Maptools.com (excellent map reading tools in convenient sizes)
U.S. Army Survival Guide FM 21-76
www.mapquest.com (get a map of a particular lat and long!)
www.magnetic-declination.com (find out latitude and longitude of any city plus magnetic declination)
About the Author Photo Credit: Garret Lucas Accessed from The Wilderness Learning Center’s Biographies page Kevin Estela has been interested in outdoor survival since he was a child. Entertained by stories from his father’s jungle survival in the Philippines during the Japanese occupation of WWII, Kevin grew up with a desire to learn more about the outdoors. At a young age and throughout adolescence, his father taught him many practical survival skills. He grew up hiking, skiing, fishing and woods bumming with friends and family. He spent over 10 years working as a seasonal kayaking and canoeing guide on the Farmington River in Connecticut and 5 years working at a busy outdoors retail sporting goods store. Kevin’s formal outdoors education includes off-road driving, winter mountaineering, hunting and firearms safety, wilderness first-aid, primitive survival skills, traditional bushcraft skills and of course wilderness survival through the Wilderness Learning Center. Kevin is a certified PADI scuba diver, avid power boater and saltwater fisherman. Kevin’s passion for education translated into teaching High School History full-time in Bristol, CT. Kevin spends as much free time as possible getting out on the water or in the woods in anyway. Whenever possible, Kevin loves to share knowledge and know how with anyone willing to listen, practice and learn. Kevin worked for one full year with us and has earned the title of Instructor. He is also a moderator on knifeforums.com and bladeforums.com where he contributes equipment reviews and shares his expertise with all. Although he isn’t officially a resident of New York, Kevin considers the Wilderness Learning Center his second home and Marty, Aggie, Bobby a second family away from his own. Kevin is a great asset to the school. His teaching style, personality, and knowledge are appreciated by all.
If you have any questions, do not hesitate to contact us!